Nitro- and amino-naphthotriazole quinones



United States Patent O NITRO- AND AMINO-NAPHTHOTRIAZOLE QUINONES MarioScalera, Somerville, and Andrew Stephen Tomcufcik and William BaptistHardy, Bound Brook, N.J., assignors to American Cyanamid Company, NewYork, N.Y., a corporation of Maine No Drawing. Application January 21,1954 Serial No. 405,493

14 Claims. (Cl. 260-308) This invention relates to new intermediates forvat dyes namely 1(N)-lower alkyl naphthotriazole-4,9-quinones and vatdyestuffs prepared therefrom.

It has been proposed in the past to prepare vat dyestuffs using ananalogue of anthraquinone as one or more I of the substituents in themolecule, the analogue being one in which one of the two benzene ringsof anthraquinone is replaced by a heterocyclic ring. In general thesedyestulfs have not enjoyed as great commercial success as theanthraquinone derivatives because they lack the enormous stability ofthe anthraquinone nucleus which contributes so much to the fastnessproperties of anthraquinone dyestuffs.

Among the heterocyclic anthraquinone analogues isnaphtholriazole-4,9-quinone which has the following formulav j 1 I O HThis compound is no more stable than other heterocyclic analogues ofanthraquinone but we have found that when the imino hydrogen of thetriazole ring is replaced by a lower alkyl group, that is to say onehaving six or less carbon atoms and the benzenoid ring is substituted inone or more of its alpha positions 5 and 8 by an amino group, I

dyestufis can be prepared which show extraordinary fastness. Apparently,the lower alkyl group destroys the reactivity of the triazole ring andthus achieves a high degree of stability which permits production of vatdyestuffs of excellent fastness. The alpha-amino-naphtho- 1-(N)-alkyltriazole-4,9-quinones may be prepared by :processes which are analogousto those used in introducing amino groups into anthraquinoue compounds,for example, the alpha position may be 'nitrated and reduced. The nitrocompounds are in themselves new compounds and are included in the scopeof the present invention.

The triazole ring itself is symmetrical in the sense that it probablyexists in tautomeric forms with the hydrogen shifting from N1 to N3 witha corresponding shift of the double bond. Once, however, the hydrogenhas been replaced by lower alkyl, the two alpha positions the 5 and 8 onthe benzenoid ring'become non-equivalent as is shown by the followingformulae a 2,879,274 ten ed. a 24. 125.?

in which R is lower alkyl. These formula represent the first step in theproduction of amino compounds by the nitration and reduction method. Ithas not been determined which isomer is preferentially formed and it isprobable that a mixture is produced. This is, however, of no importanceas the dyestulfs prepared from the intermediates always have the sameproperties. As the different isomers may be thought of as occurring withthe lower alkyl group connected with one or other of the odd numberednitrogen atoms of the triazole ring, the simplest way to represent theproducts is to show the lower alkyl group entering into the triazolering without specifying its position. This is done throughout thisspecification by using the following type of formulae:

r I N N X N R to represent isomers A and B:

NO: 0 O

. n N s N I No, 0

A B I R representing lower alkyl as above. The mononitro compound isused only for purpose of illustration and the same principlev applies toall other compounds used herein. In any event the generic formularepresents the situation where the compound is either a 5 or 8 nitroderivative. v

Typical dyestuffs which can be prepared from monoamino compounds of thepresent invention include the naphthotriazole analogue' of indanthrone.This is prepared by introducing a bromo group ortho to the NH,, groupand condensing to form the dihydroazine. The dyestuif has a much greenershade than the correspond- Another type ofdyestuflinvolvescondensationwith a halogenated benzanthrone producing first thecorresponding imine and finally the analogue to benzanthrone acridine.The production, which is effected by the usual process of alcoholicpotassium hydroxide fusion to efiect the ring closure, is shown by thefollowing equation:

l 'HN g A N R It is also possible to prepare diamino compounds in whichboth the and 8 positions are substituted by amino groups. This iseffected by first producing a monoamino compound, converting itto itsoxamidic acid derivative, which can then be subjected to furthernitration of the other alpha position in the benzenoid ring. Onreduction and hydrolysis this produces a compound having the followingformula:

mad

NHR" 0 .in' which -R-and R 'are lower'alkyl groups'andfR" is ahydroxyalkyl group. These dyestulfsshow an especially good resistance togas-fading. .-It is not-known why the superior :resistance :to'gasiading dsxobtained when ;one:. of

the benzenoid rings of the anthraquinone is changed to the alkyltriazole ring and it is not intended to advance any explanation of whythis increased stability results.

The alkylation of the triazole is carried out in the normal manner andany of the ordinary lower alkyl groups can be introduced, for example,methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl, isoamyl, andthe like. As methyl is the easiest alkyl group to be introduced and thestability is obtained regardless of which lower alkyl group is attachedto the triazole ring, the methylated derivatives are preferred.

The position on the benzenoid ring not occupied by the amino group maybe otherwise substituted by other groups such as alkyl, for example,methyl, ethyl, propyl, halogens such as chlorine and bromine and thelike. When the substituent is on the beta-position, it is theoreticallypossible to produce isomeric mixtures but the more probable event isthat the substituent will induce nitration in the alpha position nearestit.

Our invention can be illustrated by the following examples in whichparts are by weight unless otherwise indicated.

Example 1 N02 0 A solution of 31.1 parts of 1(N)-methylnaphthotriazole-4,9-quinone in 270 parts of sulfuric acidis stirred. 16.75parts of 70% nitric acid is added gradually. The exotherm of thereaction causes the temperature to ,rise and after the addition iscomplete the mixture is stirred at -105 C. until nitration issubstantially complete. The reaction mixture is then cooled and drownedin 1500 parts of ice water. The bright yellow product is isolated byfiltration, washing, and drying. A good yield of a mixture ofmononitro-l (N)-methylnaphthotriazole- 4,9-quinones is obtained.

, Example 2 N \N \CH:4 NHfl Twenty-five parts of product of Example 1 isslurried with 200 parts of ethanol and 1 part of a 10% mixture ofpalladium on charcoal is added. The mixture is then placed .under mildpressure in an atmosphere of hydrogen until reduction is substantiallycomplete. suspension is then drowned in 1000 parts of 2% sodiumhydroxide solution containing 15 parts of sodium hydrosulfite. The deepred solution is clarified by filtration to remove the catalyst and thefiltrate on aeration precipitates a goodyield of a red precipitate of amixture of amino 1(N) -methyl-naphthotriazole 4,9 quinones. This mixturemay be isolated by filtration, washing, 'and drying.

Example 3 N 0 1 0| The ethanol 1,

pond is substantially complete. The deep brown fluid mixture is thencooled and leached with 300 parts of warm water. The insoluble residueis filtered and dried.

The crude derivative of oxamidic acid thus prepared is dissolved in 110parts of sulfuric acid and stirred at -5 C., during a gradual additionof 5.6 parts of 70% nitric acid. The mixture is then held a short timeat 0-5 C. after which it is stirred and allowed to warm to roomtemperature. It is then stirred at room temperature until nitration issubstantially complete. The mixture is drowned in water to produce adull yellow precipitate, which on isolation by filtration, washing, anddrying, is found to be a good yield of nitro-oxamino- 1 (N-methylnaphthotriazole-4,9-quinone.

The crude product so isolated is dissolved in 1000 parts of potassiumcarbonate solution. This solution is then heated to 90-95 C. untilprecipitation of the mixture of nitroamino compound is complete. Thelatter is then isolated by filtration, washing, drying, and is obtainedin good yield. It may be recrystallized'from high boiling solvents.

Example 4 The nitro-amino compound produced in Example 3 is reducedcatalytically in the same manner as described in Example 2. A good yieldof l(N)-methyl-5,8-diamino naphthotriazole-4,9-quinone in the form ofits stable leuco is obtained.

Example 5 N OH; NH: 9)

Five parts of the product of Example 2 is suspended in 130 parts ofglacial acetic acid and 3.5 parts of bromine is added. The'reactionmixture is stirred at the boil for several hours and then is allowed tocool to room tem perature slowly. The precipitated product is isolatedby filtration and washing. It apparently consists of a mixture of the5-amino-6-bromo and 8-amino-7-bromo derivatives of1(N)-methylnaphthotriazole-4,9-quinone.

By reaction with cuprous chloride in alpha picoline solution, by themethod described by Hardy and Fortenbaugh in their copendingapplication, Serial No. 289,205, filed May 21, 1952, this bromo compoundcan be converted to the corresponding chloro compound.

Example 6 2.35 parts of the product of Example 5, 4 parts of anhydrouspotassium carbonate, 0.5 part of cuprous chloride, and 90 parts ofnitrobenzene are stirred at the boil until the condensation issubstantially complete. The nitrobenzene is removed by steamdistillation. The in- 'soluble residue is purified by boiling with 10%hydrochloric-acid followed by extraction with hot dichlorobenzene. Theresidual product is a dull greenish-gray solid which dyes cotton agreen-gray shade.

Example 7 N= =N cur-I l;- o :L-om N o.-

r t 0 NH NH N anddried. Theyellow dyestufi dyes cotton a reddishyellowshade.

A mixture of 4.56 parts of the product of Example 2, 4.85 parts ofl-chloranthraquinone, 3.0 parts of potassium carbonate, 0.5 part ofcopper powder, 0.5 part of iodine, and 120 parts of nitrobenzene isstirred at the boil until the condensation is substantially complete.The nitrobenzene is then removed by steam distillation and the crudeanthramide is isolated by filtering, washing, and drying. It is thenslurried in 100 parts of dry pyridine and 12 parts of aluminum chlorideis added gradually while keeping the temperature of the mixture below 60C. The mixture is then heated to reflux and held there until thecyclization is substantially complete. It is then drowned in 500 partsof 10% sodium hydroxide solution. The pyridine is removed by steamdistillation and the insoluble precipitated dyestufi is isolated byfiltration, washing, and drying. The crude dyestufl is suspended in 20%sulfuric acid solution and heated to 98 C. while 1 part of sodiumdichromate is added. The

purified dyestufi is then isolated by filtration, washing and drying. Itdyed cotton yellow-brown shades of good color value.

Example 9 NH- 0 l @A mixture of 4.5 6 parts of the 'product'ofFEXampleQ,

0.5 part of iodine, and 120 parts of nitrobenzene is stirred at refluxuntil condensation is substantially complete.

The nitrobenzene is removed by steam distillation and the dark residualproduct is isolated by filtration, washing, and drying. This crudeproduct is purified by boiling with 10% hydrochloric acid for severalhours and after filtering,'washing, and drying, by further extractionwith boiling chlorobenzene. 1.4 parts of this ipurified product is fusedwith a mixture of methanol and 50 parts of potassium hydroxide at 9095C. until thering closure is substantially complete. The reaction melt isdrowned in water and aerated until the precipitation of the dyestulf iscomplete. The precipitated dye is isolated by filtration, washing, anddrying. .Thisproductdyes. cotton a i grayish-green shade otgood colorvalue.

Example 10 "HOG:H1NH

5.6 parts of the product of'Example '4 in theform of the crude ethanolsuspension as produced in'Example4 is treated with 1.45 parts'ofmonoethanolamine and 1.85 parts of normal butylamine. The mixture isthen refiuxed until the reaction is substantially complete. 0.3 part ofcopperacetateand 0.8 part of piperidine is then added and the mixture isaerated for several hours. The mixture is then evaporated to dryness andthe blue solid residue is extracted with acetone. By diluting theacetone with water, a blue precipitate is obtained which can be isolatedby filtration, washing, and drying. It dyes celanese a violet-blue whichpossesses markedly superior resistance to gas fading.

Example I1 The procedure of Example 1 is followed, substituting 33.1parts of 1(N) ethyl naphthotriazole-4,9-quinone (prepared by the actionof diethyl-sulfate on'naphthotriazole-.4,9-quinone) for thecorresponding methyl compound. The resultant mononitro compound isthenreduced by the procedure of Example2 to giveamixture ofmonoamino-l(N) -ethylnaphthotriazole-4,9equinones.

N N ca The procedure of Example 1 is followed, using 33.1

"SCH

parts of the mixture of 1(N).,6- andl(N), 7-dimethyl-,naphthotriazole-4,9-quinones prepared by reacting 6-methylnaphthotriazole-4,9-quinone with methylsulfate. The resultantnitro compound .is reduced by the procedure of Example .2 to give amixture which is probably com- .posed of 5-aminov-1(N),.6-dimethylnaphthotriazole-4,9-

quinone and :8-amino.-1.(N), 7-dimethylnaphthotriazole- 4,9equinone.

alkyl group is methyl.

7. Alpha-nitro-alpha-amino-l(NHower alkyl-naphthotriazole-4',9-quinone.

alkyl-naphthotriazole-4,9-

alkylgroup is methyl.

'13. -Alpha-n-butylamino-alpha-Z hydroxyethylamino- 1(N)-loweralkyl-naphthotriazole-4,9-quinone.

14. A- compound having the following formula in whichR representsa loweralkyl group, X represents a substituent selected from the classconsisting of nitro and amino groups, and Y' represents a substituentselected from the class consisting of hydrogen and nitro and aminogroups.

References Cited in the file of this patent Fries et, al.: Chem.-Abst.,vol. 29, col. 3675 (1935). Waldman et al.: Chem. Abst., vol. 35, col.1791-2 (1941).

14. A COMPOUND HAVING THE FOLLOWING FORMULA IN WHICH R REPRESENTS ALOWER ALKYL GROUP, X REPRESENTS A SUBSTITUENT SELECTED FROM THE CLASSCONSISTING OF NITRO AND AMINO GROUPS, AND Y REPRESENTS A SUBSTITUENTSELECTED FROM THE CLASS CONSISTING OF HYDROGEN AND NITRO AND AMINOGROUPS.